BEETLES 179 



and bores into this a hole in which it deposits an egg, so that the larva emerges 

 amid shelter and food. The larva eats grooves into the inner layers of the roll, 

 and is full-grown in about five weeks, when it abandons the roll, and changes into 

 a pupa in the ground, where in autumn may be found the young generation 

 hibernating, to commence their ravages in the following spring. The mature insect 

 is of all the intermediate tints between silky green and blue, with golden green 

 legs and beak, and deeply punctured elytra, and is about one-third of an inch in 

 length. 



Another species of this leaf-rolling group is the branch-weevil (R. conicus), 

 which lives on pear, plum, cherry, apricot, and other fruit-trees, as well as on the 

 service-tree and the hawthorn, infesting them from the first unfolding of the blossoms 

 and leaf-buds. A little over one-eighth of an inch long, it is steel-blue in colour, 

 with long hairs; it is much punctured on the scutellum, and has on the 

 elytra stripes of spots alternating with faint dotted lines. Boring into those 

 blossoms and stalks that are an inch or two in length, in such a way that they 

 droop and wither, it lays its eggs in the leaves it rolls ; and the larvae, about five 

 weeks after the eggs are laid, drop to the ground to pass into the pupa-stage, and 

 appear next spring to begin their ravages, which sometimes extend to every tree in 

 an orchard. Another member of this family, the apple-blossom weevil (Antho- 

 nomus pomorum), lives chiefly on apple-trees, although it is also found on the haw- 

 thorn and the pear. It is blackish brown in colour with ashy grey down, showing on 

 the red elytra an oblique, whitish, black-bordered posterior band, the thighs being 

 dusky in the middle, and the scutellum small and white. Passing the winter 

 beneath stones and tree-bark, this pest bores into the young flower-buds of 

 apples, depositing a single egg in each. The injured bloom, if it develop quickly, 

 often exposes the larva, which in that case perishes, but, if it develop slowly, it 

 dries up and looks as if browned by cold or the sun. The destructiveness of the 

 larvse is therefore checked by quick development of the flowers, and increased by 

 cold weather retarding such development. In years when blossoms are plentiful, a 

 moderate number of these weevils may even be useful in destroying the super- 

 abundance of bloom, and thus preventing the development of too many, and 

 consequently the production of inferior fruit. 



Quite as injurious to trees as any of the weevils are some of the 

 Bark-Beetles. J J 



bai-k-beetles (Bostrichidce), which are very widely distributed, being 



found on high mountains apparently up to the limit of the forest-zone. All 

 have clubbed antennae and a globular, imbricated thorax. As a rule, they attack 

 such trees as have begun to decay, whether standing or fallen, but they will often 

 devote their attention to healthy trunks, though they will never touch a tree 

 that is thoroughly dry of sap. In the first warm days of spring these beetles come 

 out of their winter-quarters to pair, and by preference attack single trees standing 

 in sunny places ; into these some of the bark-beetles drive their bore only through 

 the bark, while in others they go right into the wood, the holes differing in form, 

 disposition, and length, according to the species by which they are drilled. When 

 pierced by the females for the purpose of depositing their eggs, they are called 

 " mother-galleries " : but the galleries bored by the larvae have at their ends an en- 

 largement called the cradle, in which each larva instals itself as it is on the point 



